This relates generally to imaging systems, and more particularly, to infrared imaging systems.
Conventional silicon imaging devices have a bandgap limit near a wavelength of one micron, above which they lose their ability to generate electrons from interactions with photons. These conventional devices therefore have limited capability of detecting infrared radiation from the bandgap limit through the infrared spectral region.
This has resulted in the development of two different specialized infrared imaging technologies, exotic semiconductors such as Mercury Cadmium Telluride (HgCdTe) semiconductors, Indium Antimonide semiconductors, etc. or microelectromechanical systems (MEMS) based bolometers. MEMS based bolometers typically include metal layers with differing coefficients of expansion that flex when infrared radiation is absorbed. This flexing changes the capacitance of the MEMS devices thereby allowing detection of infrared radiation by detecting the changes in capacitance.
Exotic semiconductors can have a prohibitively high cost for mass production of infrared imaging systems and cannot capture visible light images. MEMS-based bolometer devices also cannot capture visible light images.
It would therefore be desirable to be able to provide improved infrared imaging systems.